air assisted fork to non air fork conversion

Okay it's official I'm all googled out. I've got a 1982 Kz750 ltd with air pre-load front forks. I'd like to convert them to spring only with a set of progressive springs, since it's more reliable and one sides seal is leaking. I saw several references to doing this at some point but no in-depth information on how it might be done. Does anyone have a link or is it even worth the time, or should i simply replace the oil seal and live with the tempermental air assist?

Thanks for your time and help.
Glitch

Glitch wrote:

Okay it's official I'm all googled out. I've got a 1982 Kz750 ltd with air pre-load front forks. I'd like to convert them to spring only with a set of progressive springs, since it's more reliable and one sides seal is leaking. I saw several references to doing this at some point but no in-depth information on how it might be done. Does anyone have a link or is it even worth the time, or should i simply replace the oil seal and live with the tempermental air assist?

Thanks for your time and help.
Glitch

Why not just rebuild them properly. Air assist works fine and has been used forever.
If it keeps the oil in, it keeps the air in.
If your worried about one leaking down/unsafe change, then get an air balancer. It connects across the two air fill nipples and balances the air between them automatically.

I had air assist on my mk2 and it worked fine. But it leaked down after a couple weeks. In the end I put in progressive springs in and swapped the fork caps from my 76 kz750 to the mk2 and put the air assist on the 750.(They have the same forks)
That's how it's been for quite a while now, no problem.

I too would like to get rid of my air assist. I dont like the look of it on the front forks. So i would like to find out if there is a way to convert the forks. Is there anything special about the forks? or could you just weld up the hole and put good springs in them?

I messed with this for a while (I have the same bike) by making slightly longer shims (under the caps) which increased the spring rate, then just plugging the caps. Worked 'okay' but not great, so I went back to air assist. Changing out the seals is easy and cheaper then new springs, and it's pretty easy to make your own air balancer, which is simply a hose between the fittings with an air valve T fitting in between. You only have to put air in a single valve and it's balanced.

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H1Vindicator wrote:

Uh, I believe it's simple.
Just put in some new progressive springs & eschew the air.

+1 I also put in a old set of valve springs on top of the original springs. This helped to take up the loss of the air pressure.

I have a set of Progressive springs that I never used if you are interested. They are 11-1111 that have a higher preload and will not require any air.

otakar, interesting idea with the valve springs! What springs did you use, and did you use the spacer? Was it hard to get the cap back on? When I made the longer spacers it worked okay, but the forks would bottom out sometimes.

I just used a set of old 750 valve springs. I used the entire inner and outer spring assembly.I put a washer in between them so the inner spring would stay in place and the existing washer on top. I took a deep well socket and made a tool out of it which I use with a "T" handle and it makes it quite simple to install the cap.

Glitch, not trying to steal your post. One more question and I'll back off. otakar, so you left out the stock long sleeve...right?

What ever is in there you leave in there. You just add the spring. You will have to find a spring that fits your application due to the fact that different forks have different IDs. As I mentioned, I do have a set of New Extra Progressive springs if you cant make a go of this mod.